首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1197篇
  免费   68篇
  国内免费   60篇
耳鼻咽喉   2篇
儿科学   58篇
妇产科学   25篇
基础医学   93篇
口腔科学   15篇
临床医学   182篇
内科学   330篇
皮肤病学   17篇
神经病学   46篇
特种医学   254篇
外科学   72篇
综合类   30篇
预防医学   124篇
眼科学   11篇
药学   38篇
中国医学   2篇
肿瘤学   26篇
  2023年   3篇
  2022年   5篇
  2021年   17篇
  2020年   7篇
  2019年   14篇
  2018年   24篇
  2017年   13篇
  2016年   6篇
  2015年   21篇
  2014年   24篇
  2013年   37篇
  2012年   39篇
  2011年   36篇
  2010年   39篇
  2009年   38篇
  2008年   48篇
  2007年   78篇
  2006年   33篇
  2005年   55篇
  2004年   45篇
  2003年   31篇
  2002年   28篇
  2001年   24篇
  2000年   18篇
  1999年   16篇
  1998年   52篇
  1997年   37篇
  1996年   60篇
  1995年   45篇
  1994年   41篇
  1993年   51篇
  1992年   10篇
  1991年   14篇
  1990年   18篇
  1989年   28篇
  1988年   39篇
  1987年   37篇
  1986年   28篇
  1985年   31篇
  1984年   18篇
  1983年   11篇
  1982年   12篇
  1981年   22篇
  1980年   19篇
  1979年   6篇
  1978年   9篇
  1977年   15篇
  1976年   8篇
  1975年   9篇
  1974年   2篇
排序方式: 共有1325条查询结果,搜索用时 15 毫秒
91.
92.
93.
ObjectivesAcute hospitalization may lead to a decrease in muscle measures, but limited studies are reporting on the changes after discharge. The aim of this study was to determine longitudinal changes in muscle mass, muscle strength, and physical performance in acutely hospitalized older adults from admission up to 3 months post-discharge.DesignA prospective observational cohort study was conducted.Setting and ParticipantsThis study included 401 participants aged ≥70 years who were acutely hospitalized in 6 hospitals. All variables were assessed at hospital admission, discharge, and 1 and 3 months post-discharge.MethodsMuscle mass in kilograms was assessed by multifrequency Bio-electrical Impedance Analysis (MF-BIA) (Bodystat; Quadscan 4000) and muscle strength by handgrip strength (JAMAR). Chair stand and gait speed test were assessed as part of the Short Physical Performance Battery (SPPB). Norm values were based on the consensus statement of the European Working Group on Sarcopenia in Older People.ResultsA total of 343 acute hospitalized older adults were included in the analyses with a mean (SD) age of 79.3 (6.6) years, 49.3% were women. From admission up to 3 months post-discharge, muscle mass (?0.1 kg/m2; P = .03) decreased significantly and muscle strength (?0.5 kg; P = .08) decreased nonsignificantly. The chair stand (+0.7 points; P < .001) and gait speed test (+0.9 points; P < .001) improved significantly up to 3 months post-discharge. At 3 months post-discharge, 80%, 18%, and 43% of the older adults scored below the cutoff points for muscle mass, muscle strength, and physical performance, respectively.Conclusions and ImplicationsPhysical performance improved during and after acute hospitalization, although muscle mass decreased, and muscle strength did not change. At 3 months post-discharge, muscle mass, muscle strength, and physical performance did not reach normative levels on a population level. Further research is needed to examine the role of exercise interventions for improving muscle measures and physical performance after hospitalization.  相似文献   
94.
Objective:Using a novel mediation method that presents unbiased results even in the presence of exposure–mediator interactions, this study estimated the extent to which working conditions and health behaviors contribute to educational inequalities in self-rated health in the workforce.Methods:Respondents of the longitudinal Survey of Health, Ageing, and Retirement in Europe (SHARE) in 16 countries were selected, aged 50–64 years, in paid employment at baseline and with information on education and self-rated health (N=15 028). Education, health behaviors [including body mass index (BMI)] and working conditions were measured at baseline and self-rated health at baseline and two-year follow-up. Causal mediation analysis with inverse odds weighting was used to estimate the total effect of education on self-rated health, decomposed into a natural direct effect (NDE) and natural indirect effect (NIE).Results:Lower educated workers were more likely to perceive their health as poor than higher educated workers [relative risk (RR) 1.48, 95% confidence interval (CI) 1.37–1.60]. They were also more likely to have unfavorable working conditions and unhealthy behaviors, except for alcohol consumption. When all working conditions were included, the remaining NDE was RR 1.30 (95% CI 1.15–1.44). When BMI and health behaviors were included, the remaining NDE was RR 1.40 (95% CI 1.27–1.54). Working conditions explained 38% and health behaviors and BMI explained 16% of educational inequalities in health. Including all mediators explained 64% of educational inequalities in self-rated health.Conclusions:Working conditions and health behaviors explain over half of the educational inequalities in self-rated health. To reduce health inequalities, improving working conditions seems to be more important than introducing health promotion programs in the workforce.  相似文献   
95.
Longitudinal studies are characterised by repeated measurements of the outcome variable on the same individuals. This implicates that observations are correlated and that statistical techniques, such as linear regression analysis cannot be used. Special longitudinal techniques correct for the dependency in repeated observations by analysing the development of a certain individual in time. Depending on the research question, the distribution of the outcome variable, and the number of repeated measurements, a certain technique should be chosen. Sophisticated longitudinal techniques like generalized estimating equations and random-coefficient models are most recommendable.  相似文献   
96.
97.
OBJECTIVES: We evaluated the effectiveness of a minimal intervention physical activity strategy (physician-based assessment and counseling for exercise [PACE]) applied in general practice settings in the Netherlands. METHODS: Randomization took place at the general practice level. Participants were patients aged 18-70 years of age who had been diagnosed with hypertension, hypercholesterolemia, or non-insulin-dependent diabetes and had not been regularly physically active in the past 6 months. Outcome measures were assessed at baseline and at 8-week, 6-month, and 1-year follow-ups. RESULTS: No significant intervention effect over time was observed on physical activity level or stage of change for regular physical activity, and an inverse intervention effect was observed for waist circumference. However, the study population as a whole exhibited a significant increase in physical activity and a borderline significant decrease in body weight at the 1-year follow-up. CONCLUSIONS: Positive effects on physical activity level and body weight were observed, but the PACE intervention was not more effective than the standard physical activity advice.  相似文献   
98.
Objective: To determine the level of diabetes-related symptom distress and its association with negative mood in subjects participating in a targeted population-screening program, comparing those identified as having type 2 diabetes vs. those who did not. Research design and methods: This study was conducted within the framework of a targeted screening project for type 2 diabetes in a general Dutch population (age 50–75 years). The study sample consisted of 246 subjects, pre-selected on the basis of a high-risk profile; 116 of whom were subsequently identified as having type 2 diabetes, and 130 who were non-diabetic subjects. Diabetes-related symptom distress and negative mood was assessed ∼2 weeks, 6 months, and 12 months after the diagnosis of type 2 diabetes, with the Type 2 Diabetes Symptom Checklist and the Negative well-being sub scale of the Well-being Questionnaire (W-BQ12), respectively. Results: Screening-detected diabetic patients reported significantly greater burden of hyperglycemic (F=6.0, df=1, p=0.015) and of fatigue (F=5.3, df=1, p=0.023) symptoms in the first year following diagnosis type 2 diabetes compared to non-diabetic subjects. These outcomes did not change over time. The total symptom distress (range 0–4) was relatively low for both screening-detected diabetic patients (median at ∼2 weeks, 6 months, and 12 months; 0.24, 0.24, 0.29) and non-diabetic subjects (0.15, 0.15, 0.18), and not significantly different. No average difference and change over time in negative well-being was found between screening-detected diabetic patients and non-diabetic subjects. Negative well-being was significantly positive related with the total symptom distress score (regression coefficient β=2.86, 95% CI 2.15–3.58). Conclusions: The screening-detected diabetic patients were bothered more by symptoms of hyperglycemia and fatigue in the first year following diagnosis type 2 diabetes than non-diabetic subjects. More symptom distress is associated with increased negative mood in both screening-detected diabetic patients and non-diabetic subjects.  相似文献   
99.
The Institute of Medicine (IOM) recently published their report in response to an assignment “to define diagnostic criteria for Myalgic Encephalomyelitis (ME)/chronic fatigue syndrome (CFS), to propose a process for reevaluation of these criteria in the future, and to consider whether a new name for this disease is warranted”.

The basic pre-assumption of the IOM committee for the development of evidence-based diagnostic criteria for ME/CFS was that ME and CFS denote conditions with similar symptoms, hence ME/CFS.

The IOM committee recommends:

(1)?that ME/CFS will be renamed ‘systemic exertion intolerance disease’ (SEID); and that a new code should be assigned to SEID in the International Classification of Diseases (ICD), replacing the existing codes for ME (a neurological disease: G93.3) and CFS (‘signs, symptoms, and abnormal clinical and laboratory findings, not elsewhere classified’: R53.82);

(2)?that a diagnosis of SEID should be made if the new diagnostic criteria are met;

(3)?that the Department of Health and Human Services develops a toolkit appropriate for screening and diagnosing patients; and

(4)?that a multidisciplinary group re-examines the new diagnostic criteria when necessary.

This editorial reviews the working procedure of the IOM and two of the outcomes: the recommendation to introduce a new clinical entity (SEID) and new diagnostic criteria.

Based upon the contents of the report, and the arguments of the IOM, a search of PubMed and the archive of the Journal of Chronic Fatigue Syndrome using the search terms ME (and old synonyms) and CFS, and a search of PubMed related to the five core symptoms of SEID was conducted.

Reviewing the working method and the recommendations, it is concluded that the new diagnostic criteria for SEID are based upon important methodological shortcomings and that the introduction of SEID to replace both ME and CFS has several profound negative consequences outweighing the advantages.  相似文献   
100.
Interpeduncular fossa sign: CT criterion of subarachnoid hemorrhage   总被引:1,自引:0,他引:1  
Yeakley  JW; Patchall  LL; Lee  KF 《Radiology》1986,158(3):699-700
A retrospective study of 100 cerebral computed tomography scans interpreted as displaying subarachnoid hemorrhage was undertaken to determine the frequency of blood in the interpeduncular fossa as a useful radiographic sign. The results indicate that the interpeduncular fossa sign is second only to blood in the Sylvian fissure-circular sulcus area as a reliable indicator of subarachnoid hemorrhage on CT scans.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号